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TI-2026-85021 Aliases CVE-2026-115448GHSA-4ppq-6vhc-4q97

Unbounded recursion in Apache ZooKeeper snapshot serialization

Priority MEDIUM 45CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-770.

Summary

Apache ZooKeeper from 3.8.0 before 3.8.8 and from 3.9.0 before 3.9.7 is affected. The server serializes its data tree to a snapshot by recursing once per znode level with no depth bound, a case of CWE-770. A client allowed to create znodes can build a chain of nested znodes deep enough to exhaust the JVM stack during a snapshot, and the default open root ACL permits this. Because the deep tree is rebuilt from the transaction log on restart, the server fails again while taking the startup snapshot and cannot return to service, and recovery may cause data loss; the same log affects followers, so the failure can spread across an ensemble.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

Uncontrolled recursion in Apache ZooKeeper. The server serializes its data tree to a snapshot by recursing one stack frame per znode level, with no depth bound. A client permitted to create znodes (the default root ACL is open) can build a chain of nested znodes deep enough that taking a snapshot exhausts the JVM stack and kills the snapshot thread; sizes stay within jute.maxbuffer, so existing limits do not prevent it. This is a denial of service that becomes persistent: on restart the server rebuilds the deep tree from its transaction log and fails again while taking the startup snapshot, so it does not return to service, and recovery can entail data loss. The same log affects a leader and its followers, so it can spread across an ensemble. This issue affects Apache ZooKeeper 3.8.0 through 3.8.7 and 3.9.0 through 3.9.6. Users are recommended to upgrade to 3.8.8 or 3.9.7, which fix the issue. As a workaround, use ACLs and authentication to restrict znode creation rather than relying on the default open root ACL.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0061 49th percentileScored 2026-11-08
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
ApacheApache ZooKeeper3.9.0 – 3.9.6; 3.8.0 – 3.8.7—No fix listedCNA
  • Apache ZooKeeper VendorApache Affected 3.9.0 – 3.9.6; 3.8.0 – 3.8.7 Fixed in — No fix listed CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:*——Apache
  • cpe:2.3:a:apache:zookeeper:*:*:*:*:*:*:*:* Versions — — ·Apache

Remediation

Upgrade to 3.8.8 or 3.9.7, which fix the issue. As a workaround, restrict znode creation with ACLs and authentication instead of relying on the default open root ACL. Red Hat AMQ Broker 7, Red Hat Fuse 7, Red Hat Offline Knowledge Portal and Red Hat OpenShift AI (RHOAI) are affected, with Red Hat's plan listed as none available.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat AMQ Broker 7AffectedNo fix yet
Red Hat Fuse 7AffectedNo fix yet: Fix deferred
Red Hat Offline Knowledge PortalAffectedNo fix yet
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Not affected: 1 product
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-11-04 Threatist record created from CVE-2026-115448
  2. 2026-11-04 Alias added: GHSA-4ppq-6vhc-4q97
  3. 2026-11-04 CISA SSVC decision points changed
  4. 2026-11-04 Affected versions changed · Red Hat
  5. 2026-11-04 CVSS score added · Red Hat
  6. 2026-11-05 Affected versions changed · Red Hat
  7. 2026-11-06 Affected versions changed · CNA

References

Advisory 1

  • TI-2025-18529 Apache Tomcat: Potential RCE and/or information disclosure and/or information corruption with partial PUT KEVCVSS 3.1CRITICAL 10.0
  • TI-2024-30292 Apache OFBiz: Confused controller-view authorization logic (forced browsing) KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-26062 Apache OFBiz: Unauthenticated endpoint could allow execution of screen rendering code KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-21190 Apache OFBiz: Path traversal leading to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2024-18186 Apache HugeGraph-Server: Command execution in gremlin KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-25106 Deserialization of untrusted data in Apache ActiveMQ KEVCVSS 3.1CRITICAL 10.0
See all 4053 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences